Field of the Invention
The present invention relates to a technique to correct an image blur caused by a camera shake of an apparatus.
Description of the Related Art
Camera shake compensation functions of an image capturing apparatus include an optical camera shake compensation function and an electronic camera shake compensation function; the former detects a camera shake (angular vibration) and shift vibration of the apparatus and moves a corrective optical system so as to offset the detected camera shake and shift vibration, whereas the latter cuts out an image in each frame of moving images in a direction for cancelling an image blur caused by the camera shake.
In the electronic camera shake compensation, it is important to synchronize each frame of moving images with a timing for acquiring a camera shake signal. As the synchronization cannot always be established, it is also important to prepare a handling method for a case in which the synchronization cannot be established, e.g., when the acquisition of the camera shake signal is delayed.
In Japanese Patent Laid-Open No. 2007-114466, camera shake compensation is performed using predicted camera shake signals in a case where the differences between the predicted camera shake signals and the actual camera shake information indicate repetition of sign inversion within a fixed time period, and camera shake compensation is performed using a fixed correction amount in a case where the differences are equal to or larger than a fixed value within the fixed time period. That is to say, in Japanese Patent Laid-Open No. 2007-114466, the predicted signals are not used and images are centered using the fixed correction amount in a case where the magnitude of camera shake signals is large due to, for example, unidirectional panning, and camera shake compensation is performed using the predicted signals only in other cases.
Incidentally, according to Japanese Patent Laid-Open No. 2007-114466 described above, a CPU that is involved in the calculation for predicting the camera shake signals at the time of capturing moving images is subjected to a large calculation processing load.